Learning Forum

[zainulhassan74]

I defined a bolt preload of 37.5kN for M12 bolt on my flang model. average stress value should be around 330MPa for bolt after pretensioning but maximum stress is around 440MPa. Total deformation is around 1mm with rubber gasket and large deflction on.

I have studs in my mode with bonded contact between studs and nuts, studs and flange. There is frictional contact between flange and two face of gasket, nut and flange face.

Note. maximum stress is not on the edge of contact between bolt and nut

[deepak.deepak]

Hi,

Review the bolt material properties and ensure they are accurately defined in your model. Additionally, how you model the bolt and preload can significantly affect the simulation results. Proper modeling and analysis of bolted connections, including the consideration of bolt preload effects, are crucial for evaluating the structural integrity of assemblies. Make sure that the pretension load is at the middle of the shank, by scoping the geometry properly. Please cross-check the bolt preload calculations based on standard procedure. 

Please refer to the Ansys courses on bolt pretension: Modeling the Bolt and Preload | Ansys Innovation Courses| Connecting Bolts with the Rest of an Assembly | Ansys Courses| Preloaded Bolted Joint Analysis | Ansys Innovation Courses.

Thanks

Deepak.